1. Field of the Invention
The present invention relates to a radiation imaging apparatus using radiation and a radiation imaging system.
2. Description of the Related Art
Recently, there have been advances in manufacturing techniques of liquid crystal display panels that use switching elements such as thin-film transistors (TFTs). There is a trend towards enlargement of panels and display units. These manufacturing techniques have been applied to large area sensors having conversion elements such as semiconductor conversion elements and switching elements. This has led to the full digitalization of such fields as the radiation imaging apparatus field (see Japanese Patent Laid-Open No. 2006-4998).
Conversion elements used in radiation imaging apparatuses can be divided into direct and indirect types. A direct conversion element directly converts radiation into electric charges. An indirect conversion element carries out radiation-to-electric charges conversion of radiation such as visible light that has undergone wavelength conversion using a wavelength conversion device such as a scintillator. Examples of direct conversion elements include amorphous selenium, gallium arsenide, gallium phosphate, lead iodide, mercury iodide, CdTe, and CdZnTe. Examples of indirect types include MIS conversion elements and PIN conversion elements. When converting visible light into electric charges, it is common for an amorphous silicon (a-Si) layer to be used as the conversion element.
At the same time, because the radiation imaging apparatus outputs images by digitally converting minute signals, there may be deterioration of the S/N ratio of a captured image if there is even a small amount of noise in the minute signals. In particular, because a bias line connected to a conversion element and a signal line connected to a switching element are prone to becoming noise sources, countermeasures against these kinds of lines had been sought in order to reduce noise.
As a result of dedicated research in noise arising from bias lines and signal lines, the present inventors discovered that noise may be generated if these lines were placed in a specific alignment structure.